Conventionally, a recovery device for a nozzle head has a cap, the cap covers a nozzle face of the nozzle head on which a plurality of nozzle groups are formed. This cap realizes a capping process by contacting a tip end of an annular sealing lip formed of elastic material to the nozzle face. Moreover, as described in Japanese Publication of Unexamined Patent Applications No. JP-A-11-314376, an inside area of the sealing lip is partitioned by partitioning lip into a plurality of compartments, so that a plurality of the nozzle groups can be enclosed in these compartments for respective groups. The compartments comprise the suction openings for liquids respectively, the suction openings are communicated with exterior sucking unit independently from one another. And, when a negative pressure is created inside the sealing lip, it is possible to suck the liquids independently from the respective nozzle groups by way of the respective suction openings.
The recovery device comprising such a cap has following disadvantages. In case where the nozzle groups on the nozzle face (for example, rows of the nozzles) are increased in number in order to improve a performance of the nozzle head, an area of the cap must be increased correspondingly, which is undesirable from a view point of making the device compact. Moreover, in case where the area of the cap is increased, a bottom of the cap tends to be deformed due to the negative pressure created in the cap and comes into a state warped toward the nozzle face, when the liquids are sucked from the nozzle groups through the respective compartments. Therefore, there is such anxiety that the bottom of the cap may get in touch with the nozzle face, and the following countermeasures are considered.
(1) To provide a distance between the bottom of the cap and the nozzle face, by increasing heights of the sealing lip and the partitioning lips.
(2) To suppress deformation by increasing thickness of the bottom of the cap.
(3) To suppress deformation by bonding a plate of rigid material (such as stainless steel) to a back face of the bottom of the cap.
(4) To enhance rigidity by integrally molding the cap with a holder for holding the cap.
(5) To employ rubber having high hardness, as material for the cap.